Recovery of proteids from waste liquors of the hide-treating art



C. L. PECK.

RECGVEPY 0F PROTEIDS FROM WASTE LIQUORS OF THE HIDE TREATING ART. APPLICATION FILED JULY 20. I9I8.

1,847,822; Patented July 27, 1920 727/2/7 ery 5/00Z( Swvewfoz flrrow s a citizen of the United'stateg'residirii g at UNITED STATES PATIENT OFFICE.

CHARLES LEE PECK, or NEW YORK, N. Y; ASSIGNOR. T0 THE Dona COMPANY,

NEW YORK, N. Y., A CORPORATION or DELAWARE.

RECOVERY OF PROTEIDS FROM WASTE LIQUORS OF HIDE-TREATING ART.

To all whom it'may concern:

[Be it known that I, CHARLES LEE PnoK,

New York city, in the county of New or k, State of New York, have invented certain newand useful Improvements in the Recovery of Proteids from "Naste Liquors of the Hide-Treating Art; andI do hereby declare the following to be a full, clear, and

exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

In my application for Letters Patent of the United States, Serial No. 219,981, filed March 2, 1918, is set forth a method for the recovery of water-insoluble non-putrescible 'proteids from the waste liquors of the hide-- treating art. Such waste liquors of the hide-treating art (say from the hide-cleansing process or; from the hide-glue process, preliminary totanning of the hide) 0ontain proteid'matter and lime salts.

The method described in'said application consists in first separating such liquors by sedimentation into an effluent, carrying proteids partly in solution and partly in sus- ,pension, and a sludge containing caustic lime and calcium salts, hair, fleshings, and fragments of 'hide inaterial together with fatty or greasy material and some sand and other foreign matter. The efiiuent is then treated with a waste liquor effluent from the tanning process, whereupon the proteids are precipitated as a sludge insoluble in water.

After the effluents have been taken over from the proteid sludge and from the lime sludge, both slud es still contain a considerable quantity 0 moisture, a portion of which it is desirable to eliminate, from one or the other, or from both, before admixing them in the next step ofthe process; it being desirable that the mixture oontain as little as say 40 to 50% of moisture, so that it may seem almost dry. Thus, for instance, the desired reduction in the moisture content of the mixture may be cheaply and effectively produced by exposing the proteid sludge in a relatively thin layer to the drying action of the open air, and then mixing with it. the lime sludge, in the proportions below given,

-so as to have a total moisture content, as

(sodium hydrate) which is found to exercise Specification of Letters Patent. 7 I Patented'July 27, 192() Application filed July 20, 1918. Serial No. 245,854.

a moisture content of say 25%) and 50 parts by weight of lime sludge (having a moisture content of say 70%) will present suitable proportions for the purposes of the invention, that is to say, will constitute a mixture wherein there is present and distributed throughout the mass a suflicient quantity of the calcium salts to'r-eact efficiently with the proteids present in the mixture. Heat facilitates the reaction, and, upon raising the temperature of the mass to the boiling point of water, it is found that a considerable proportion of the proteids is made water-soluble, so that the portion thus converted is im- .sludge. This is probably due to reaction between the lime present and thesoda'ash re sulting in the formation of caustic alkali a still more effective action upon the pro-' teids in converting them into Water-soluble or available condition. Furthermore, those ingredients of the lime sludge which contain nitrogenous matter, such as the hair, fleshin addition to its availability, as described, 100

as a fertilizer, is rendered non-putrescible by continuing the application of heat thereto for a sufiicient length of time and at a sufiiciently high degree to not only dry it I thoroughly, but to destroy the bacteria pres- 105 ent.

A special characteristic of the invention is that it permits the utilization of the lime slud 'e, not only for the recovery of the ferti izer values contained therein, but also 110 ings, and hide'substances, are dissolved by as a source of lime in a, caustic' condition for reaction with the proteid sludge and also for reaction with the soda ash inthe production of caustic alkali (sodium hydrate) with its still greater efficiency in the conversion of the proteids to the water-solu-- ble condition and forits saponifying effects.

In the accompanying drawing is shown a flow .sheet indicating diagrammatically the steps of the process. In this drawing, A indicates the sedimentation tank wherein the waste liquors from the hide-treating art are received and wherein their lime sludge is sep arated from thesupernatan't efliuent. B indicates the tank or cistern for the storage and sedimentation of the waste liquors from the tanning rocess. C indicates the reaction tank or clstern wherein the combined eflluents from the tanks or cisterns A and B are received and wherein the proteids held in solution and in suspension in the efliuent from tank A are recovered. as a proteid" sludge or precipitate insoluble in water. D indicates the apparatus (of any suitable type, not shown) in which the miX- ture of the sludges, or the mixture of the sludges together with soda ash, is heated and eventually dried. 7

It will be understood that some of the advantages of the invention may be obtained by substituting caustic lime, or caustic lime and soda, ash, or caustic limeand potash, or causticalkali, for the lime sludge in the treatment of the precipitated proteids, or by substituting (in whole or in part) a-sludge containing caustic lime or 'caustic alkali, but obtained from some other source than the waste liquors of the lime process of the hide treating art. These substitutions I regard as within the broader scope of the invention, although they obviously lack the more specific advantages hereinbefore' recited, incident to the use 0 the sludge from the hide-treating art.

WVhat I. claim is:

1. The method of recovering, from the waste liquors of the lime process of the hide- 't reating art, material available for use as a fertilizer, WlllCll consists in separating said liquors into a sludge and an effluent, precipitating the proteids contained in said efiluentby subjecting them to the action of the waste liquors from the tanning process,

and then heating the. precipitated proteids in-the presence of sodium hydroxid,

2. The method of recovering, from the waste liquors of the lime process of the hide-treating art, material available-for use as a fertilizer, which consists in separating said l quors into a sludge and an efliuent, precipitating the proteids contained in said efliuent by subjecting them to the action of the waste liquors from the tanning process,

effluent by subjecting them to the action of precipitating the proteids contained .in said the waste liquors from the tanning process, v

and then heating the precipitated proteids in admixture with said sludge together with an alkali metal carbonate; substantially as described.

In testimony whereof I aflix m si nature.

CHARLES LE P CK. 

